There is provided a swinging rotor as a rotor for a centrifugal separator. The swinging rotor is formed by a rotor yoke and a bucket. Tubes each containing a sample are inserted into the bucket, and the bucket is formed in a bottomed cylindrical shape and detachably and pivotably attached to the rotor yoke. The tubes are accommodated in the bucket while they are held in a rack. The bucket is swung up by the centrifugal force up to an angle of 0 to 90° along with the rotation of the rotor.
As described in, for example, patent literature 1, there is provided a bucket including a shield cover for sealing the interior of the bucket as this conventional type of bucket. The reason why the interior of the bucket is sealed is to prevent toxic bacteria, toxic substance, and the like from leaking outside the bucket and prevent other substances from entering the tubes without caps.
The shield cover described in patent literature 1 is formed in a shape that covers the opening of the bucket body in the bottomed cylindrical shape, and detachably attached to the bucket body by clip type fixing tools. A portion of the shield cover, which is mated with the bucket body, is provided with a seal member. When this seal member is sandwiched between the bucket body and the shield cover, the sealability is ensured.
To attach the shield cover to the bucket body, the clip type fixing tools described in patent literature 1 or screw type attachment structures are often used. The clip type fixing tools disclosed in patent literature 1 are each formed in a lever shape to be pivotably supported by the bucket body, and are formed to be engageable with the engaging portions of the shield cover. When the clip type fixing tools engage with the engaging portions of the shield cover, the shield cover is fixed to the bucket body.
With the screw type attachment structures, when each flange of the bucket body and a corresponding flange of the shield cover are fastened by a bolt while they are superimposed on each other, the shield cover is fixed to the bucket body. As the screw type attachment structure, there is also provided an attachment structure in which an external thread formed in the opening of one member among the shield cover and the bucket body threadably engage with an internal thread formed in the other member. In this case, the shield cover is attached/detached by rotating the shield cover with respect to the bucket body.
An operation of attaching the shield cover to the bucket body is performed in a so-called safety cabinet or the like. The safety cabinet indicates a simple work chamber having a working space as a negative pressure environment. To attach the shield cover to the bucket body, the tubes each containing the sample are accommodated in the bucket body together with the rack. Then, the bucket body is covered with the shield cover, and the shield cover is attached using the above-described attachment structures. By attaching the shield cover to the bucket body in this way, the interior of the bucket is sealed.
The centrifugal treatment of the samples is performed by carrying, from the safety cabinet to the rotor yoke, the bucket to which the shield cover is attached, and mounting the bucket on the rotor yoke. After the centrifugal treatment, the bucket detached from the rotor yoke is carried again to the safety cabinet, and the shield cover is then detached from the bucket body. During the centrifugal treatment or the carriage operation, it is necessary to ensure the sealability of the interior of the bucket. It is also important to readily carry the bucket.